1. Field of the Invention
The field of this invention lies within the art of self contained breathing apparatus sometimes referred to as an SCBA. Such self contained breathing apparatus generally has a pressurized tank of air that is regulated through a first stage regulation to an intermediate pressure which is thereafter regulated to the user by a demand or second stage regulator. The SCBA's of the prior art have incorporated a mask or lens having a nozzle or connector for delivering gas from the second stage regulator to the interior of the mask. The user relies upon a given pressure being provided from the pressurized breathing gas tank, which can be monitored to provide a given reading to the user of the amount of pressure in the tank. This invention specifically relates to the use of SCBA's and the monitoring of the tank pressure through a logical visually readable output.
2. The Prior Art
The prior art with regard to displays for self contained breathing apparatus, (SCBA) have fallen into a number of categories.
Some of these categories have provided an analog display that can be lit or the use of a simple gauge like device. Others use analog pressure gauges which are connected to the tank of air. Still further, some utilize the aspects of a shutter or a series of lights that show a respective amount of air in the breathing gas tank and move in response to a pre-established position to indicate a particular amount of gas remaining.
In some cases, displays have incorporated a moving dial for indicating a particular amount of pressure established from a pressure transducer or other interconnect.
Some of the most recent efforts in this regard to provide a display have been enunciated in U.S. Pat. No. 5,097,826 issued to Robert E. Gray, et al issued Mar. 24, 1992 and U.S. Pat. No. 6,032,664 issued to Robert E. Gray, et al issued Mar. 7, 2000.
U.S. Pat. No. 5,097,826 sets forth a pressure monitoring device. This particular pressure monitoring device while incorporating a transducer and a lighting display is such where it does not logically function for purposes of providing a readable output. One of the problems with U.S. Pat. No. 5,097,826 is that it shows a series of lights along side a user which can occlude the user's field of view. Occluding the user's field of view results in loss of vision. The diminution of the field of vision creates a problem for the user. Also, the U.S. Pat. No. 5,097,826 does not have a logic system for determining the particular gauge like functions which can be responded to in a substantially more user friendly relationship.
U.S. Pat. No. 6,032,664 incorporates a display for an SCBA. However, in this particular patent it is specifically directed toward the aspects of providing a display that can be seen within the field of vision of a single eye of a user. It is stated that by doing this, the position is preferred and prevents the user from seeing a double image.
To the contrary, this invention specifically does not limit the view to a user's single eye as in U.S. Pat. No. 6,032,664.
When considering the non-logical aspects of the prior art displays as well as the reduction in the field of vision and other characteristics that do not provide adequate spacing and reading of a display, it will be seen that this invention is a substantial step over the art for allowing a user to quickly determine remaining air supply.
This improved display does not reduce the field of vision and can be easily seen by a user by looking downwardly into the mask.
Another object of this invention is that the split display is logically intuitive. A user knows readily whether or not the air supply is greater or less than fifty percent. The fifty percent threshold is an important decision point for the user during fire suppression and rescue activities.
A further object of this invention is for the display to provide an external low air alarm so that others can determine if the user's air supply is below a pre-determined level.
Another object of this invention is to eliminate the reduction of the field of vision by those displays which are placed around a lens which obstructs the field of vision.
A further object of this invention is to provide a split display which is incremental on either side in a logical manner within a user's field of vision.
A further object of this invention is to sense the ambient light to regulate the amount of light of the display.
Another object of this invention is to provide a mechanical engagement of the nozzle system and display so that it is oriented correctly and cannot be placed in an upside down or offset position.